Power operated can opener with variable shut-off



Dec. 24,1963 w. J. LANDRY 3, 4 972 POWER OPERATED CAN OPENER WITH VARIABLE SHUT-OFF Filed Nov. 16, 1959 2 Sheets-Sheet 1 26 20 2.9 o /fi A T'TORNEK Dec. 24, 1963 w. J. LANDRY 3,114,972

POWER OPERATED CAN OPENER WITH VARIABLE SHUT-OFF Filed NOV. 16, 1959 2 Sheets-Sheet 2 ATTORNEK United States Patent 3,114,972 POWER OPERATED CAN OPENER WITH VARIABLE SHUT-OFF William J. Landry, 9tl-A Lake Tapawingo, Blue Springs, Mo. Filed Nov. 16, N59, Ser. No. 853,374 Claims. (Cl. 304) This invention relates generally to electrically powered can openers and refers more particularly to improvements therein with respect to determining and controlling the length of the cutting or lid severing operation.

The usual practice in electrically powered can openers is to provide the unit with a simple on-oif control which is manipulated by the operator to commence and stop the operation of the can feeding mechanism in accordance with the observed results obtained. In most cases the control governs a motor which is coupled by a direct drive to the can feeding mechanism, feeding commencing when the motor is energized, and stopping upon deenergi- Zation of same. In such units the supply of power to the can feeding mechanism continues so long as the control is maintained in the on position.

One of the objects of the present invention is to provide an improved electrically powered can opener in which is provided means for limiting the operation of the feed mechanism to a positively prescribed period, which period can be varied in accordance with the size of the can to be opened, and to produce either partial or complete severance of the lid from the can. One of the features of my invention is that while the operator is left free to stop the operation of the unit at any point within the prescribed or selected period, nevertheless, once the end of the period is reached, the feeding of the can is halted automatically and independently of any further manipulation of the controls by the operator. Through the invention, overrunning of the desired length of cut is effectively prevented, with the advantages that in the case of partial cuts of a given length, these can be accurately obtained, and in the case of complete severance, there still will be no power wasting and functionally useless continued feeding of the can once the severance has been completed.

Another object of the invention is to provide in can openers of the character described a means of conditioning the functioning of the unit upon the manipulation of two control elements rather than one, thus making it more unlikely that small children can accidentally start the unit. It is a feature of the invention that upon termination of one complete cutting operation, the unit cannot again be started until the cut selecting control element is manually returned to a functioning position. Stated otherwise, the unit is so designed that after use the unit is normally in an inoperative condition and can only be rendered operable by resetting the cut selector control.

A further object of the invention is to provide an unusually simple and reliable mechanism for accomplishing the foregoing results. It is a feature of the invention in this connection that the automatic shut-off control is actuated in response to the rotation of the feed wheel of the can feeding mechanism, the control causing shutoff after a preselected number of revolutions of the feed wheel. The control and its associated operating mechanism are further so arranged that the selection of and adjustment to the proper period of operation is accomplished with ease and facility.

Still another object of the invention is to provide mechanism for the purposes set forth which can be incorporated into certain presently known can openers without requiring any basic re-design or re-tooling.

Other and further objects of the invention, together "ice with the features of novelty appurtenant thereto, will appear in the course of the following description.

In the accompanying drawings which are to be read in conjunction with the instant specification, and in which like reference numerals indicate like parts in the various views;

FIG. 1 is a front elevation of a typical electrically powered can opener incorporating the features of my invention;

FIG. 2 is a side elevation taken from the left-hand side of FIG. 1, the casing being shown in section;

FIG. 3 is a fragmentary side elevation taken from the right-hand side of FIG. 1;

FIG. 4 is an enlarged fragmentary rear view of the main power control assembly;

FIG. 5 is an enlarged top plan view of the complete can opener unit, the casing removed to expose the elements contained within;

FIG. 6 is a fragmentary view taken generally along the line 66 of FIG. 5 in the direction of the arrows;

FIG. 7 is a fragmentary view taken along the line 77 of FIG. 5 in the direction of the arrows;

FIG. 8 is a fragmentary sectional view taken along the line 8-8 of FIG. 6 in the direction of the arrows; and

FIG. 9 is a diagrammatic showing of the elements of the electrical circuit and control mechanism therefor.

Referring now to the drawings, my invention will be described in connection with an electrically powered can opener of the type disclosed in the patent to Aberer et al., No. 2,902,757, issued September 8, 1959. All of the details of the basic can opener structure and operating mechanism are described in full in that patent, and will not be repeated here except as necessary to clarify their relationship with the elements of the present invention.

Generally speaking, the can opener unit includes a base Stilt, from the forward edge of which rises an essentially vertical support structure 11 which serves the purpose of supporting at its upper end the operating mechanism of the can opener. This mechanism includes a rotary feed wheel 12, with which cooperates a cutter wheel 13. While the feed wheel is mounted for rotation about a fixed axis, the cutter wheel is carried by a plate structure 16 which is operable in response to manipulation of a hand lever 17 to separate the cutter wheel from the feed wheel to permit insertion of a can rim therebetween, and to again bring the two together so as to pierce the can lid preparatory to starting rotation of the feed wheel. The position of the hand lever 17 and plate structure illustrated in the present drawings is that which obtains after the lid has been pierced, but before power is supplied to the feed wheel.

As disclosed in the aforementioned patent, the plate structure 16 and hand lever 17 operate as a unit capable of limited rotary displacement in a clockwise direction (FIGS. 4 and 9) about the axis of the feed wheel. The connection between the two is established by means of providing on the back of the plate structure a rearwardly struck boss 19 (FIG. 4), the upper edge of which is engaged by the lower edge 17a of the hand lever 1'7, whereby depression of the outer end of the lever, as by force F, will cause the plate structure to move in the same direction. The hand lever and plate structure are biased and normally maintained in the illustrated position by a tension spring 20 which is connected at one end with a lug 21 extending rearwardly from the vertical mounting structure 11, and at the other end with a similar lug 16a secured to and extending rearwardly from the movable plate structure 16. A large aperture 11a is provided in the mounting structure 11 to accommodate and permit free movement of the lug 16a, plate structure 15, and hand lever 17.

Located in the downward path of the lug 16a is the free end of an elongate actuator 22 for a normally open snap-acting switch S having the fixed contact 23 and movable contact 24. The details and manner of operation of such a switch are fully disclosed in the aforesaid Patent 2,902,757. For the purposes of this application, it is enough to know that the movable contact is closed against the fixed contact on depression of the hand lever 17, the lug 16a striking and displacing the actuator 22 to produce closing of the contacts. The movable contact 23 returns to the opened position when pressure is removed from the hand lever, permitting the latter to return to its normal condition.

As Will later be explained in more detail, the hand actuated switch just described is included in an electrical circuit (FIG. 9) which governs the operation of an electric motor 25. The motor 25 is vertically oriented on the base and terminates in a drive shaft 25a equipped with a gear worm 26. The worm drivingly engages the teeth of a gear 27 secured to a horizontal axle or shaft 28. The feed wheel 12 is secured to the other end of shaft 28 so that there is established a direct drive between the motor and feed wheel.

Preferably the gear 27 is constructed of nylon or other tough plastic. It is secured to the shaft 28 by means of a flanged collar 29 press-fitted onto the end of the shaft, the gear body being secured to the collar by screws 3%. Forwardly of the gear, the shaft is journaled in a housing 11b which forms a part of the vertical mounting structure 11.

As may best be seen in FIGS. 6-8, inclusive, the inner or forward face of the gear 27 is provided with a spiral groove 27a which spirals about the axis of rotation. The groove provides a non-circular camming surface which, during operation of the unit (as will later be described), cooperates with a stylus 31a carried by a pivotal arm 31. The arm 31 is pivoted by a stud 32a to a stationary support bracket 32 disposed parallel with but spaced inwardly of the gear. The arm 31 lies on the opposite side of bracket 32 from the gear, the stylus extending through an elongated arcuate slot 32b in the bracket. The slot is curved about the pivot axis of the arm so as to permit free movement of the stylus therein.

The outer end of the arm extends through an elongate vertical slot 33 formed in the side of the outside casing C of the unit. A knob 3112 may be included on the outer end of the arm to facilitate operation. A calibrated scale is inscribed on the outer surface of the casing adjacent the slot, the scale providing an index against which the position of the stylus in the groove can be determined. More will be said of this later.

It will be observed that the dimensions of arm 31 and the location of its pivot stud 32a are such that upon pivoting of the arm, the stylus 31a moves approximately radially of the feed wheel shaft 28, and thus transversely of the spiral groove in the gear 27 (see FIG. 7). To provide sufiicient freedom for the stylus that it can be shifted in and out of adjacent grooved portions when the gear is stationary, the arm 31 is permitted limited movement axially of its stud 32a. However, the arm is biased toward the gear by means of a compression spring 34 which encircles the stud.

From the description thus far, it will be evident that the arm 31 constitutes an adjustable element which can be positioned to initially seat the stylus in the spiral groove of the stationary gear at progressively greater or lesser distances from the axis of rotation of the gear. The spring biased wobble mounting of the arm permits transverse adjustment of the stylus across the grooves in response to simple vertical pressure on the external knob 31b. The stylus will ride in and out of the adjacent groove portions because of the free mounting on the stud, but will always seat in the base of the groove where it comes to rest under the influence of spring 34.

The direction of the spiral groove is such that when rotation of the gear is started in response to energization of motor 25, the groove will cause the stylus, if it has been shifted away from the axle 28, to move inwardly toward shaft 28. The inward movement of the stylus is gradual since it is being acted upon by the spiral camming surface, but will continue until the stylus reaches the inward end of the groove. The displacement of the stylus, and consequently arm 31, is thus a function of the rotary displacement of the feed wheel shaft subsequent to energization of the motor. The number of revolutions of the feed wheel shaft required to bring the stylus to the inner end of the groove will vary according to the initial manual placement of the stylus, the number being greater as the stylus is placed further and further away from the shaft.

As can perhaps best be understood by referring first to FIG. 9, the arm 31 serves the purpose of an adjustable control element for a second switch S having fixed contact 35 and movable contact 36. The switch S is in series with the main power switch S The switch S is essentially identical in construction with switch S having the elongate actuator 37 (FIG. 6). The switch is carried on a support member 38, secured to the bracket 32 as by the inturned ear 32c and screw 38a. The lower end of the support member rests on one of the horizontally extending legs 32:! and 32a of the bracket 32, which are in turn secured rigidly to horizontal flats formed on the vertical support structure 11 as by screws 39.

It will be noted, again referring to FIG. 6, that the actuator 37 of switch S has its free end positioned adjacent a shoe-like member 40 secured to and forming a part of the inner end of the arm 31. The shoe 40 is so designed that when the arm is in the inner position (stylus at the inner end of the groove), which is the position illustrated in FIG. 6, the contacts 35 and 36 remain open. However, the curvature of shoe 40 is such that when the arm 31 is pivoted clockwise (as seen in FIG. 6), the actuator 37 will be engaged and depressed, thus closing contacts 35 and 36. This condition of the contacts obtains immediately upon the initial pivoting of the arm, and will remain so no matter how far out on the gear face the stylus is moved. The contacts are opened only upon return of the arm to the inner limit of its counter-clockwise motion. When the shoe arrives at this location, it permits the actuator 37 to return to its normal position, and the contacts to open, under the influence of the return spring incorporated in the switch.

In usin the can opener to perform its functions, the first step taken is to set the selector arm 31 at the position which will produce the length of cut desired. Normally the scale adjacent the slot 33 will be calibrated in terms of can sizes, which means that simply by comparing the position of the arm with the scale and moving the arm to the desired calibration, the unit is now ready to produce a cut of the length desired. If only a partial cutting is sought, the arm will be positioned short of the marker for the particular can involved, the differential depending on how far around the cut is to go. The setting of the arm 31 determines the position of the stylus 31a on the gear.

As has been earlier mentioned, the movement of the arm out of its normal position serves also to close the switch S Power can now be supplied to motor 25 by simply depressing the hand lever 17 which closes switch S and completes the circuit to the motor. This initiates rotation of the gear 27 and the feed wheel 12, with the result that the can begins to feed through the cutter wheel. The rotation of the feed wheel will continue (if the hand lever remains depressed) until such time as the stylus 31a reaches the inner end of the spiral groove and switch S is thereby opened to break the circuit to the motor, causing the motor to stop and halting the rotation of the feed wheel.

It is, of course, possible to stop the motor at any time before the automatic shut-off takes place simply by releasing the pressure on the hand lever 17.

Once the stylus 31a has reached the inner end of the groove, the motor remains inoperative until the stylus is reset by manipulation of arm 31 in the fashion described. The likelihood of accidental starting of the unit by children or by inadvertent striking of the hand lever is substantially minimized. Further, it insures that care will be taken to adjust the arm 31 to the proper position for each new cutting operation.

From the foregoing it will be seen that this invention is one well adapted to attain all of the ends and objects hereinabove set forth together with other advantages which are obvious and which are inherent to the structure.

It will be understood that certain features and subcombinations are of utility and may be employed without reference to other features and subcombinations. This is contemplated by and is within the scope of the claims.

As many possible embodiments may be made of the invention without departing from the scope thereof, it is to be understood that all matter herein set forth or shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense.

Having thus described my invention, I claim:

1. In a power operated can opener, an electric motor having a rotary drive shaft equipped with a gear worm, a gear drivingly engaged by the worm, a feed wheel rotatively coupled with the gear, switch means operable to start and stop said motor, a spiral groove formed in one face of said gear having as its center the axis of rotation of the pinion, a swingable control element supported adjacent said one face and having a stylus adapted to be received in said groove, said control element being manually shiftable to move said stylus transversely of the groove and toward or away from said axis of rotation to position the stylus at various locations in the groove, other switch means controlled by said control element and operable to cause stopping of said motor independently of said first switch means when the stylus reaches a selected location in the groove toward one end thereof.

2. In a power operated can opener, an electric motor, a rotary feed wheel coupled with said motor and driven thereby, an electrical circuit governing the starting and stopping of said motor, said circuit including manually operable switch means for closing the circuit and starting the motor, and mechanism actuated responsive to the rotation of said feed wheel subsequent to the starting of said motor and operable to cause the motor to stop following a selected number of revolutions of said feed wheel, said mechanism including other switch means operable to open said circuit independently of the first named switch means.

3. In a power operated can opener, an electric motor, a rotary feed wheel coupled with said motor and driven thereby, an electrical circuit governing the starting and stopping of said motor, said circuit including manually operable switch means for closing the circuit and starting the motor, a rotary camming member also coupled with and driven by said motor, a camming surface on said camming member, a movable control element engageable with said camming surface, said camming surface causing movement of said control element upon rotation of said camming member, and a second switch means in said electrical circuit operable to cause stopping of said motor in response to a selected displacement of said control element by said camming surface.

4. The combination as in claim 3 wherein said control element is manually adjustable to initially engage said control element with said camming surface at different locations whereby to vary the time interval over which said motor operates.

5. In a power operated can opener of the type having an electric rotary drive means and a feed wheel connected with said drive means and rotated in response to energization of said drive means, the combination therewith of first switch means electrically connected with said drive means and operable to energize same whereby to initiate rotation of said feed wheel, and mechanism actuated response to the rotation of said feed wheel and operable to ale-energize said drive means upon completion of a selected number of revolutions of said feed wheel following energization of said drive means, said mechanism including a camming member driven by said drive means, second switch means in series with the first named switch means, and a control element engaged by said camming member and movable thereby, said control element operably associated with said second switch means and operable to actuate same to cause the deenergization of said drive means upon a selected degree of movement of said camming member.

References Cited in the file of this patent UNITED STATES PATENTS 

1. IN A POWER OPERATED CAN OPENER, AN ELECTRIC MOTOR HAVING A ROTARY DRIVE SHAFT EQUIPPED WITH A GEAR WORM, A GEAR DRIVINGLY ENGAGED BY THE WORM, A FEED WHEEL ROTATIVELY COUPLED WITH THE GEAR, SWITCH MEANS OPERABLE TO START AND STOP SAID MOTOR, A SPIRAL GROOVE FORMED IN ONE FACE OF SAID GEAR HAVING AS ITS CENTER THE AXIS OF ROTATION OF THE PINION, A SWINGABLE CONTROL ELEMENT SUPPORTED ADJACENT SAID ONE FACE AND HAVING A STYLUS ADAPTED TO BE RECEIVED IN SAID GROOVE, SAID CONTROL ELEMENT BEING MANUALLY SHIFTABLE TO MOVE SAID STYLUS TRANSVERSELY OF THE GROOVE AND TOWARD OR AWAY FROM SAID AXIS OF ROTATION TO POSITION THE STYLUS AT VARIOUS LOCATIONS IN THE GROOVE, OTHER SWITCH MEANS CONTROLLED BY SAID CONTROL ELEMENT AND OPERABLE TO CAUSE STOPPING OF SAID MOTOR INDEPENDENTLY OF SAID FIRST SWITCH MEANS WHEN THE STYLUS REACHES A SELECTED LOCATION IN THE GROOVE TOWARD ONE END THEREOF. 